Morphological Changes of The Tricuspid Valve Complex in Functional Tricuspid Regurgitation On Contrast-Enhanced Computed Tomography

Background: Whether it is possible to perform morphological evaluation of functional tricuspid regurgitation (FTR) on contrast-enhanced computed tomography (CT) was examined by evaluating the relationships between the parameters measured by contrast-enhanced CT and TR severity on transthoracic echocardiography.Methods: Fifty patients underwent contrast-enhanced CT. Tricuspid annulus area (TAA), tricuspid annulus circumference (TAC), right ventricular volume (RVV), and the distances between the tips and bases of the papillary muscles were measured on contrast-enhanced CT in diastole and systole. Fifty cases were divided into 34 in the TR ≤ mild group (none TR: 3 cases, trivial TR: 24 cases, mild TR: 7 cases), and 16 in the TR ≥ moderate group (moderate TR: 8 cases, severe TR: 8 cases) using the TR grade measured by transthoracic echocardiography, and then differences between the groups were examined.Results: Significant differences were found in TAA, TAC, and RVV (p<0.01) and the distances between the tips of the anterior and posterior papillary muscles (p<0.05) in both diastole and systole. Since the septal papillary muscle could not be identified in 18 cases (36.0%), only the distance between the anterior and posterior papillary muscles was measurable in all cases. On subgroup analysis, risk factors for FTR ≥ moderate were evaluated by multiple logistic regression analysis. The risk factors identified in the multivariable risk factor analysis were diastolic RVV (odds ratio 1.083 [95% confidence interval 1.029-1.139]) and systolic RVV (odds ratio 0.951 [95% confidence interval 0.906-0.997 ]).Conclusions: TAA, TAC, RVV, and the distance between the tips of the anterior and posterior papillary muscles measured on contrast-enhanced CT were shown to be significantly increased in the TR ≥ moderate group. Detailed morphological assessment of FTR is possible by contrast-enhanced CT.

Insights into diastolic function analyses using cardiac magnetic resonance imaging: impact of trabeculae and papillary muscles

Background This cardiovascular magnetic resonance (CMR) study investigates the impact of trabeculae and papillary muscles (TPM) on diastolic function parameters by differentiation of the time-volume curve. Differentiation causes additional problems, which is overcome by standardization. Methods Cine steady-state free-precession imaging at 1.5 T was performed in 40 healthy volunteers stratified for age (age range 7–78y). LV time-volume curves were assessed by software-assisted delineation of endocardial contours from short axis slices applying two different methods: (1) inclusion of TPM into the myocardium and (2) inclusion of TPM into the LV cavity blood volume. Diastolic function was assessed from the differentiated time-volume curves defining the early and atrial peaks, their filling rates, filling volumes, and further dedicated diastolic measures, respectively. Results Only inclusion of TPM into the myocardium allowed precise assessment of early and atrial peak filling rates (EPFR, APFR) with clear distinction of EPFR and APFR expressed by the minimum between the early and atrial peak (EAmin) (100% vs. 36% for EAmin < 0.8). Prediction of peak filling rate ratios (PFRR) and filling volume ratios (FVR) by age was superior with inclusion of TPM into the myocardium compared to inclusion into the blood pool (r2 = 0.85 vs. r2 = 0.56 and r2 = 0.89 vs. r2 = 0.66). Standardization problems were overcome by the introduction of a third phase (mid-diastole, apart from diastole and systole) and fitting of the early and atrial peaks in the differentiated time-volume curve. Conclusions Only LV volumetry with inclusion of TPM into the myocardium allows precise determination of diastolic measures and prevents methodological artifacts.

Morphometric study on papillary muscles of human tricuspid valve-dissection method

Aim of the present study was to observe the measurements of anterior papillary muscles present in tricuspid valve of human heart. Measurements of anterior papillary muscles in tricuspid valve gains utmost importance in cardiac surgeries because they are the causes of myocardial infarction in recent times because of its variations and detection of these causes by advent in modern technologies which will help in treatment of tricuspid valve diseases. This study was carried out on 96 normal formalin fixed human heart specimens. Dissection was performed according to standard techniques. Anterior papillary muscles were observed and length, width and thickness of each muscle were measured and documented. In the present study, numbers of anterior papillary muscles were present with a frequency of 1-3, with most common appearance of 1 muscle in 66 hearts (68.8%) and least common incidence of 3 muscles in 6 hearts (6.3%). Anterior papillary muscles were present in all 96 hearts. In measurements, anterior papillary muscles mean height was 1.49±0.44 cm; mean width was 0.82±0.21 cm and mean thickness was 0.64±0.15 cm respectively. We hope this study will serve to understand the morphometry of anterior papillary muscles better and will help in various surgical procedures and cardiac treatment done on tricuspid valve.

A cadaveric study on chordae tendinae of human tricuspid valve

Aim of the present study was to observe the types of chordae tendinae present in tricuspid valve of human heart. Morphology of chordae tendinae in tricuspid valve gains utmost importance in cardiac surgeries in recent times because advent in modern technologies in treatment of tricuspid valve diseases.This study was carried out on 96 normal formalin fixed human post-mortem heart specimens. Types of chordae tendinae observed on the basis of their attachments.Chordae tendinae were observed in all specimens. Five types of chordae tendinae were identified namely rough zone, free edge, fan shaped, deep and basal chordae. Anterior papillary muscle was seen providing attachment to 2 to 9; Posterior papillary muscles were seen with 1 to 6 and Septal papillary muscles provided attachment to 1 to 4 chordae tendinae.We hope this study will serve to understand the tricuspid valve complex and types of different chordae tendinae better and it will help in various surgical procedures done on tricuspid valve.

Mitral valve prolapse morphofunctional features by cardiovascular magnetic resonance: more than just a valvular disease

Introduction Mitral valve (MV) prolapse (MVP) is a primary valvular abnormality. We hypothesized that additionally there are concomitant abnormalities of the left ventricle (LV) and MV apparatus in this entity even in the absence of significant mitral regurgitation (MR). Objective To characterize MV and LV anatomic and functional features in MVP with preserved LV ejection fraction, with and without significant MR, using cardiovascular magnetic resonance (CMR). Methods Consecutive MVP patients (n = 80, mean 52 years, 37% males) with preserved LV ejection fraction, and 44 controls (46 years, 52% males) by CMR were included, as well as 13 additional patients with “borderline” MVP. From cine images we quantified LV volumes, MV and LV anatomic measurements (including angle between diastolic and systolic annular planes, annular displacement, and basal inferolateral hypertrophy) and, using feature tracking, longitudinal and circumferential peak systolic strains. Results Significant MR was found in 46 (56%) MVP patients. Compared with controls, MVP patients had LV enlargement, basal inferolateral hypertrophy, higher posterior annular excursion, and reduced shortening of the papillary muscles. LV basal strains were significantly increased, particularly in several basal segments. These differences remained significant in patients without significant MR, and many persisted in “borderline” MVP. Conclusions In patients with MVP and preserved LV ejection fraction there is LV dilatation, basal inferolateral hypertrophy, exaggerated posterior annular displacement and increased basal deformation, even in the absence of significant MR or overt MVP. These findings suggest that MVP is a disease not only of the MV but also of the adjacent myocardium.

Comprehensive left ventricular outflow tract management beyond septal reduction to relieve obstruction

The surgical management of patients with hypertrophic obstructive cardiomyopathy can be extremely challenging. Relieving the left ventricular outflow tract obstruction in these patients is often achieved by performing a septal myectomy. However, in many instances, septal reduction alone is not enough to relieve the obstruction. Interventions on the sub-valvular apparatus, including the anomalous chordae tendineae and the abnormal papillary muscles, are often required. In this review, we summarize the embryology and the pathophysiology of the different elements that may contribute to the left ventricular outflow tract obstruction in the setting of hypertrophic obstructive cardiomyopathy. In addition, we highlight the different surgical procedures that a surgeon may adopt to relieve the left ventricular outflow tract obstruction, beyond the septal myectomy.

Transverse tubule remodelling in the atrophied left ventricle in right‑sided heart failure

Right-sided heart failure is a common consequence of pulmonary arterial hypertension. Overloading the right ventricle results in hypertrophy, which progresses to failure characterised by impaired Ca2+ dynamics and force production that is linked with transverse(t)-tubule remodelling. This also unloads the left ventricle, which consequently atrophies. Experimental left‑ventricular unloading can result in t-tubule remodelling, but it is currently unclear if this occurs in right-sided heart failure. In this work, we studied the monocrotaline (MCT)-induced right heart failure in the rat, using confocal microscopy to investigate cellular remodelling of t-tubules, junctophilin-2 (JPH2), and ryanodine receptor-2 (RyR2). We examined remodelling across tissue anatomical regions of both ventricles: trabeculae, papillary muscles, and free walls. Our analyses demonstrated in MCT hearts significant loss of t-tubule periodicity, disruption of the normal sarcomere striated pattern with JPH2 labelling, and also a disorganised striated pattern of RyR2 - a feature not previously reported in heart failure. Remodelling of JPH2 and RyR2 in the MCT heart was more pronounced in papillary muscles and trabeculae - particularly in the left ventricle, indicating that these anatomical structures, used as ex vivo isolated muscle preparations, are more sensitive to the disease process.